The word that springs to mind is "CityBird", who used to run low cost trips out of BRU to LAX, MIA and I think MCO.... where are they now?
FWIW, I work as a business consultant in this sector, and I think Neo hit the nail squarely on the head. The LCAs won't get a toehold in the long haul sector because the majors won't let them.
A prediction - the LCAs may turn out to be the "dot coms" of the airline business... remember ValuJet?
TA